Immunoprofile of Adenocarcinomas of the Endometrium, Endocervix, and Ovary With Mucinous Differentiation

Primary Endometrial Gastric (Gastrointestinal)-type Mucinous Adenocarcinoma: A Detailed Clinicopathologic and Molecular Analysis of 27 Cases

Endometrial gastric (gastrointestinal)-type mucinous adenocarcinoma (EmGA) is rare and was introduced as a new entity in the latest World Health Organization (WHO) classification of female genital tumors. Herein, we report a detailed clinicopathologic, immunohistochemical, and molecular study of 27 EmGA, the largest published series to date. The cohort consisted of 27 patients (median age 69 y; range 42 to 87 years). Histologically all cases showed gastric/gastrointestinal differentiation with foamy apical cytoplasm with distinct cell borders (n=21), goblet cells (n=9), signet ring cells (n=4), and Paneth cells (n=1). Using FIGO grading, 5 were grade 1, 14 grade 2, and 8 grade 3. Tumors were positive for MUC6 (10/21), CK7 (22/24), CK20 (16/24), CDX2 (24/26), and Claudin 18 (9/12). In all, 12/27 exhibited aberrant p53 expression and 3/26 showed MLH1 and PMS2 loss, including 2 with confirmed MLH1 gene promoter methylation. Next-generation sequencing showed pathogenic variants in TP53 (13/20), KRAS (7/20), PIK3CA (5/20), BRCA2 (4/20), SMAD4 (3/20), and POLE (1/20). Using TCGA classification (based on cases with available molecular results), 1/20 was POLE mutated, 2/20 were mismatch repair deficient (MMRd), 4/20 were no specific molecular profile (NSMP), and 13/20 were TP53 abnormal. FIGO stage (2009 staging system) ranged from IA to IVB. Outcome data (21 patients; follow-up of 2 to 77 mo) showed that 2 patients died of disease at 14 and 46 months after diagnosis, 1 patient died from other causes at 28 months, 8 were alive with disease, and 10 were alive with no evidence of disease. Like the cervical counterpart, primary EmGA has a distinctive morphologic appearance, harbors frequent TP53 mutations, and can be associated with adverse outcomes despite low-grade morphology and/or low-stage at presentation. They may be represented in all 4 TCGA molecular groups.

Serous endometrial carcinoma metastatic to the sigmoid colon masquerading as a primary colon cancer detected by bowel obstruction

BACKGROUND

The majority of colorectal malignancies are primary tumors. Secondary tumors are rare, and colorectal metastasis from endometrial carcinoma is exceptionally uncommon. We report a case of serous endometrial carcinoma that metastasized to the sigmoid colon, initially presenting as a primary colon carcinoma due to bowel obstruction.

CASE PRESENTATION

A 79-year-old woman presented with abdominal distention and constipation. Five years earlier, she had undergone an open total hysterectomy with bilateral salpingo-oophorectomy for endometrial serous carcinoma. A colonoscopy revealed stenosis encircling the entire sigmoid colon. Abdominal computed tomography demonstrated irregular wall thickening in the sigmoid colon with enhanced regional lymph node enlargement and upstream bowel dilatation. Peritoneal dissemination in the pelvis was also noted. To relieve the obstruction, two self-expanding metal stents were inserted. Subsequently, due to the presumed diagnosis of sigmoid colon carcinoma with peritoneal dissemination, an open left hemicolectomy with resection of the peritoneal dissemination was performed. Histopathological examination identified the colon tumor and peritoneal dissemination as metastatic serous endometrial carcinoma. Immunohistochemical studies showed the tumor cells were negative for CK7, CK20, and CDX2. No chemotherapy was administered, and 6 months post-operation, no recurrence was observed.

CONCLUSIONS

Metastasis of endometrial carcinoma to the colon is extremely rare. Diagnosing a colon tumor as a metastasis from endometrial carcinoma is challenging during preoperative examinations. Therefore, in patients with a history of endometrial carcinoma, the possibility that the primary site might be the uterus should be considered.

Expression Patterns of Cytokeratins (CK7, CK20, CK19, CK AE1/AE3) in Atypical Endometrial Hyperplasia Coexisting with Endometrial Cancer

Few studies have evaluated cytokeratin's (CK) staining patterns in atypical endometrial hyperplasia (AEH) coexisting with early-stage endometrial cancer (EC). We aimed to assess the staining patterns of selected CKs (CK7, CK19, CK20, CK AE1/AE3) in 74 patients with coexisting AEH and EC by independently analyzing both morphological variables. Specimens were collected from women with AEH and EC who underwent surgical interventions between 2012 and 2019 at the Department of Obstetrics and Gynecology of Vilnius University Hospital "Santaros Klinikos" in Vilnius, Lithuania. Immunostaining was also qualitatively classified as being heterogeneous or intense. The results revealed heterogeneous CK7 expression in all AEH cases and intense staining in 95.95% cases of AEH. The heterogeneous expression of CK7 was detected in all EC specimens. Intense CK7 expression was observed in 95.09% cases of EC G1 and in all G2 ECs. Heterogenous CK19 expression was present in all AEH specimens with intense staining in 92.42% of cases. Heterogeneous CK19 expression was observed in all EC samples with intense expression in 86.27% cases of EC G1 and 100% cases of EC G2. Interestingly, a significant relationship was found when comparing the heterogeneous expression of CK19 between AEH and well-differentiated EC. A significant difference was reported in the intense expression of CK AE1/AE3 (p = 0.031; p = 0.029) between AEH and G2 ECs and in the intense expression of CK AE1/AE3 between G1 and G2 ECs. CK20 staining was not a characteristic feature for AEH and early-stage EC. CK staining is present either in AEH or in early-stage endometrioid-subtype EC in different manners. Heterogeneous CK19 expression was significantly more common in AEH than in EC. CK20 expression was not associated with either AEH nor early-stage EC. An intense expression of CK AE1/AE3 was mainly present in moderately differentiated ECs, whereas the intense reactivity of AE1/AE3 showed a significant difference in well to moderately differentiated uterine tumors. The clinical implication of CK staining may aid in the more accurate diagnosis of AEH and early-stage EC as well as detect micrometastases leading to better oncological outcomes.

Adenocarcinomas of the Gynecologic Tract Involving the Urinary Bladder: A Series of 16 Cases Potentially Mimicking Urothelial Malignancy

CONTEXT.—

There is limited literature describing gynecologic adenocarcinomas involving the urinary bladder and potential diagnostic pitfalls.

OBJECTIVE.—

To describe key features distinguishing metastatic (or extension of) gynecologic adenocarcinomas from urothelial carcinomas with glandular differentiation.

DESIGN.—

Retrospective review of surgical pathology cases of gynecologic adenocarcinomas involving the bladder from 2 different institutions, retrieved from surgical pathology archives, was performed. Morphologic features were recorded, along with immunohistochemistry results when available. Electronic medical records were reviewed for clinical and radiographic information.

RESULTS.—

Sixteen cases of gynecologic adenocarcinomas (9 endometrial endometrioid adenocarcinomas, 4 endometrial serous carcinomas, 2 high-grade tubo-ovarian serous carcinomas, and 1 cervical adenosquamous carcinoma) involving the bladder were identified. All included cases had mucosal involvement potentially mimicking primary bladder neoplasms, including 4 cases originally diagnosed as urinary carcinomas. Tumors expressed keratin 7 (12 of 13; 92%), PAX8 (11 of 12; 92%), estrogen receptor (11 of 15; 73%), p16 (8 of 11; 73%), progesterone receptor (8 of 14; 57%), GATA3 (5 of 12; 42%), and p63 (3 of 11; 27%); all tumors were negative for keratin 20 (0 of 12). Features supportive of Müllerian origin included prior history of gynecologic malignancy, lack of morphologic heterogeneity in nonendometrioid tumors, and immunophenotypic coexpression of PAX8 and estrogen receptor with absent GATA3. Potential pitfalls seen in a subset of cases included misleading radiologic and cystoscopic findings, replacement of the overlying urothelial mucosa by tumor mimicking precursor lesions, focal GATA3 and/or p63 positivity, and areas of squamous differentiation in tumors of endometrioid histology.

CONCLUSIONS.—

A combination of clinical history, certain morphologic features, and proper selection of immunohistochemical stains is key for the correct diagnosis of secondary gynecologic adenocarcinomas involving the urinary bladder.

Mixed Ovarian Neoplasms With Gastrointestinal-type Mucinous and Mullerian Epithelial Components: A Rare Group of Tumors Demonstrating the Phenotypic Plasticity of the Mullerian Epithelial Cell

Primary mucinous ovarian neoplasms, gastrointestinal-type (GI-type), are composed of mucin-producing tumor cells resembling intestinal goblet cells or gastric foveolar epithelium. In contrast to seromucinous tumors, which exhibit endocervical-type mucinous differentiation and are thought to be derived from endometriosis, the cell/tissue-of-origin of most GI-type mucinous ovarian tumors is unknown. We identified 8 GI-type mucinous ovarian tumors (cystadenomas, n=4; borderline tumor/carcinoma, n=4) with spatially distinct areas that showed morphologic features of Mullerian-type epithelial differentiation (ciliated cells or endometrioid-type glands). Immunohistochemistry for cell lineage markers and Alcian blue (pH 2.5)/Periodic Acid-Schiff staining were performed. Morphologically distinct components were isolated by microdissection, from which extracted DNA was analyzed by targeted next-generation sequencing. In all cases, immunohistochemistry demonstrated mucin-producing cells to be positive for at least one GI marker (CK20 or CDX2), while areas with morphologic features of Mullerian differentiation were positive for PAX8, ER and/or PR, and lacked expression of CK20 and CDX2; CK7 was strongly and diffusely positive in all tumor cells. Tumor cells with a gastric-type phenotype produced neutral mucin, while acidic mucin was present within intestinal-type goblet cells. Targeted sequencing revealed ARID1A mutations in all mixed borderline tumors/carcinomas (n=4); other recurrent genetic alterations included KRAS (n=2) and TP53 mutations (n=2). Shared mutations were present in paired Mullerian and GI-type mucinous tumor components in 4 mixed borderline tumors/carcinomas, with more shared mutations between components than private mutations specific to each component. All mixed borderline tumors/carcinomas were associated with endometriosis (n=3) or Mullerian inclusion cysts (n=1); mutation or loss of ARID1A expression was seen in these putative precursor lesions in 2 cases. Hence, ovarian neoplasms composed of clonally related GI-type mucinous and Mullerian-type epithelial components harbor ARID1A mutations and are frequently associated with endometriosis. The existence of a Mullerian stem/progenitor cell with the capacity to differentiate toward cell lineages within the GI-tract may be involved in the pathogenesis of at least a subset of GI-type mucinous ovarian neoplasms.

Primary endometrial gastric (gastro-intestinal)-type carcinoma: A practical approach

The latest WHO classification of the female genital tract tumors introduces a new type of carcinoma: the primary gastric-type (or gastro-intestinal type) carcinoma of the endometrium. This type of neoplasm tends to have a poor outcome, making its correct diagnostic important. As little is known about this entity and given its quite challenging diagnosis, we aim to review existing data about it and propose a practical diagnostic approach. There are currently 11 cases published in 8 articles fitting the precise definition of a primary gastric-type carcinoma of the endometrium. Three main differential diagnoses must be excluded before considering this tumor: endometrioid adenocarcinoma with mucinous (Müllerian-type) differentiation, endocervical primary, and gastro-intestinal primary. Morphological aspects of this tumor can be heterogeneous and confusing; in this context, immunochemistry can be helpful to highlight the gastric or intestinal differentiation, but also to eliminate a mucinous endometrioid adenocarcinoma of Müllerian-type, by the constant negativity of estrogen receptors. A metastasis of a primary gastro-intestinal tract carcinoma must also be excluded by clinical, endoscopic and imaging work-up. Finally, an endometrial extension of a primary endocervical gastric-type carcinoma should be ruled out by complete sampling of the cervix. Intestinal type endocervical adenocarcinoma is easier to eliminate since this is an HPV-associated neoplasm.

Mucinous Proliferations of the Uterine Corpus: Comprehensive Appraisal of an Evolving Spectrum of Neoplasms

A variety of endometrial lesions may contain mucinous cells. Herein, the author reviews the literature on the classification and clinicopathologic significance of uterine corpus proliferations with a significant mucinous component, assesses the 2020 World Health Organization classification of such lesions, and presents a diagnostic framework. The key epithelial mucinous lesions include mucinous metaplasia, atypical mucinous glandular proliferation and mucinous carcinoma. Each of these categories are classifiable into "usual" and gastrointestinal subtypes, the latter being indicative of intestinal (presence of goblet cells) and/or gastric-type (abundant, pale eosinophilic or clear cytoplasm and well-defined cell borders) morphology. It has been proposed that at least focal expression of gastrointestinal immunohistochemical markers be required for all gastrointestinal type lesions, and for gastrointestinal type atypical mucinous glandular proliferation and carcinoma, minimality or absence of estrogen receptor expression, and the absence of an endometrioid component. Mucinous carcinomas of the usual type, in which >50% of the tumor is comprised of a mucinous component, are the most common. Morphologic subtypes include mucinous carcinoma with microglandular features and mucinous carcinoma with signet rings (signet ring carcinoma). Endometrioid carcinomas with a less than a 50% mucinous component are classified as endometrioid carcinoma with mucinous differentiation. Several studies have directly compared endometrioid and mucinous carcinomas, the latter presumably of the usual type, with respect to patient outcomes after treatment. All have found no difference in overall and disease free survival between these groups. However, three major studies have found mucinous carcinomas to be associated with a higher risk of lymph node metastases. Nineteen cases of mucinous carcinoma of the gastrointestinal type have been reported, and the limited data on their follow-up after primary treatment suggests that this subtype is more clinically aggressive and should accordingly be classified separately from mucinous carcinomas of the usual type. The morphologic spectrum of mucinous carcinoma of the gastrointestinal type is unclear and continues to evolve. Mucinous change, which may sometimes be extensive, may also be associated with papillary proliferation of the endometrium, adenomyoma of the endocervical type, atypical, and typical adenomyomas. In a curettage or biopsy, intestinal type mucinous epithelium may be indicative of any of the gastrointestinal lesions mentioned above, but may also represent samplings of uterine teratomas, yolk sac tumors, genital and extragenital adenocarcinomas with intestinal differentiation, or low-grade appendiceal mucinous neoplasms that secondarily involve the endometrium.

The Lifestyle Modifications and Endometrial Proteome Changes of Women With Polycystic Ovary Syndrome and Obesity

Polycystic ovary syndrome (PCOS) is a polyendocrine disorder and the most common endocrinopathy in women of reproductive age. Affected women have an elevated prevalence of being overweight and obese. Our study sought to determine how weight loss associated with lifestyle changes affects the endometrium specific proteome, endocrine-metabolic characteristics, and motor capabilities of obese women with PCOS and infertility. A group of 12 infertile women under the age of 38 with PCOS and BMI ≥30 kg/m² were included in the study. An evaluation was performed by a gynecologist and an endocrinologist. The weight-loss program lasted 8 weeks under the guidance of a professional trainer. Endometrial sampling during a period of implantation window for proteome determination was performed before and after weight loss. In endometrial samples at the end of the study increased protein abundance was recorded for Legumain, Insulin-like growth factor-binding protein 7, Hepatocyte growth factor receptor, Keratin, type II cytoskeletal 7, and Cystatin-B, while the B-lymphocyte antigen CD20 protein abundance decreased. Our results also indicate significantly lowered fasting blood glucose level and free testosterone concentration and significant improvements in body composition and physical capacity. This study may open up the venues for investigating important biomarkers that may affect endometrial receptivity.

CLINICAL TRIAL REGISTRATION

https://clinicaltrials.gov/ct2/show/NCT04989244?term=NCT04989244&draw=2&rank=1, identifier: NCT04989244.

Immunohistochemistry in gynecologic carcinomas: Practical update with diagnostic and clinical considerations based on the 2020 WHO classification of tumors

This review provides an update on immunohistochemistry applications-diagnostic, prognostic, and predictive-in the pathology evaluation of gynecologic carcinomas. The 5th edition of the WHO Classification of Female Genital Tumors introduced important changes in the diagnostic classification of lower genital tract, endometrial, and ovarian carcinomas, with major influence on the routine pathology practice. Lower genital tract carcinomas and their precursor lesions are now classified based on their human papillomavirus (HPV)-associated and HPV-independent pathogenesis, reflecting the clinically significant prognostic differences and impacting the therapeutic decision-making. Immunohistochemical markers have an increasing role in the pathology evaluation of endometrial carcinomas: in addition to their traditional use in the differential diagnosis and histologic subtyping, they have also been recently advocated for prognostic classification as surrogates for the TCGA (The Cancer Genome Atlas) molecular groups. New entities - mesonephric-like adenocarcinoma and gastric (gastrointestinal)-type mucinous adenocarcinoma of the endometrium - have also been added and often require immunostains for diagnostic confirmation. Ovarian carcinomas frequently show overlapping morphologic patterns and heterogeneous appearance within the same tumor, necessitating immunohistochemical work-up. Beyond diagnostic applications, there is increasing clinical demand for screening of inherited cancer syndromes, prediction of prognosis and guiding targeted therapy. Practical issues and pitfalls related to mismatch repair protein immunohistochemistry, HER2, and PD-L1 testing are also discussed.

Endometrial Gastric (Gastrointestinal)-type Mucinous Lesions: Report of a Series Illustrating the Spectrum of Benign and Malignant Lesions

With the recent elucidation of gastric-type lesions in the female genital tract (especially in the cervix), occasional cases of endometrial adenocarcinoma displaying gastric (gastrointestinal) differentiation have been reported, but they are currently not recognized as a distinct pathologic entity. We report 9 cases of endometrial mucinous lesions which exhibit gastric (gastrointestinal)-type features by morphology and immunohistochemistry, including 4 adenocarcinomas and 5 benign mucinous lesions, in patients aged 32 to 85. The adenocarcinomas showed gastric-type morphology in all 4 cases and goblet cells in 1, with a component of benign gastric-type mucinous glands in 1 case. Immunohistochemically, the adenocarcinomas were positive for CK7 (4/4), CEA (4/4), MUC6 (3/3), PAX8 (3/4), CK20 (2/4), CDX2 (2/4), and estrogen receptor (1/4). They were negative for Napsin A (0/3), with mutation-type p53 staining in 2/4 cases, block-type p16 positivity in 1/4, and scattered chromogranin-positive cells in 1/2. Targeted next-generation sequencing revealed nonsense mutation in RB1 gene for the case with block-positive p16. Follow-up was available in all adenocarcinoma cases and indicated aggressive behavior; 2 patients were dead of disease at follow-up of 7 months to 3 years, 1 was alive with progression at 9 months, and 1 was alive without disease at 7 months. The benign mucinous lesions (including the benign component in 1 adenocarcinoma) exhibited gastric-type morphologic features in 5/6 cases, goblet cells in 5/6, and Paneth-like neuroendocrine cells in 1/6. These benign mucinous lesions were associated with an endometrial polyp in 5/6 cases. Cytologic atypia was present in 2/6 cases and a lobular architecture resembling cervical lobular endocervical glandular hyperplasia in 4/6. Immunohistochemically, the benign mucinous lesions were positive for CK7 (5/5), CDX2 (5/6), estrogen receptor (4/5), MUC6 (4/5), CK20 (3/5), PAX8 (3/5), and CEA (2/4), with scattered chromogranin-positive cells in 4/4 cases; in all cases tested Napsin A was negative, p53 was wild-type and p16 was negative. We propose the term "endometrial gastric (gastrointestinal)-type adenocarcinoma" for this distinctive group of rare aggressive endometrial carcinomas. We believe that benign or atypical gastric (gastrointestinal)-type mucinous lesions are putative precursors for these adenocarcinomas, comparable to recognized premalignant gastric-type lesions in the cervix and the vagina. Future recognition and reporting of these gastric-type endometrial mucinous lesions will help delineate their pathogenesis and clinical significance.

SMARCA4-deficient uterine sarcoma: A case report and a concise review

Background

SMARCA4-deficient uterine sarcoma (SDUS) is a newly discovered undifferentiated uterine mesenchymal malignancy which has loss of expression of SMARCA4.

Case

A 46-year-old woman presented with heavy irregular vaginal bleeding over the previous 5 months. Computed tomography and magnetic resonance imaging showed a large pelvic mass centered within the uterus, suspicious of malignancy with regional metastatic lymphadenopathy. Biopsy confirmed SDUS and patient underwent chemotherapy. Her symptoms improved 3 months after treatment.

Conclusion

An extremely rare case of this newly described entity is reported. Recognizing the characteristic imaging and pathology findings of SDUS is essential for an accurate diagnosis, which may affect patient survival.

Cervical Glandular Neoplasia: Classification and Staging

Endocervical adenocarcinomas (EAs) account for 25% of all primary cervical carcinomas. Approximately 85% of EAs are driven by high-risk human papillomavirus (HPV) infection, the most common of which is the so-called usual type endocervical adenocarcinomas. Non-HPV-driven subtypes harbor distinct clinicopathologic features and prognosis and have been increasingly recognized in recent years, which has led to efforts to improve classification of EA based on clinically relevant and reproducible criteria. This review discusses a recently proposed classification system, the International Endocervical Adenocarcinoma Criteria and Classification, which uniquely integrates morphology, cause/pathogenesis, and biological behavior of HPV and non-HPV-driven subtypes of EA.

Mucinous adenocarcinoma of the endometrium with metastasis to the clitoral glans after pelvic exenteration for radiation resistant vaginal cuff recurrence

Mucinous adenocarcinoma of the endometrium (MACE) is a rare subtype of endometrial adenocarcinoma that often presents a significant diagnostic challenge due to its variation from the conventional morphologic appearance of endometrioid epithelium. This case report is of a woman who has survived 4 years after pelvic exenteration and subsequent vulvectomy for recurrent MACE.

•

Mucinous Adenocarcinoma of the Endometrium is a rare subtype of endometrial cancer.

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It poses a significant diagnostic challenge due to its variation from typical features.

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This is a case of MACE with persistent recurrence despite radiotherapy and surgery.

Massively parallel sequencing analysis of mucinous ovarian carcinomas: genomic profiling and differential diagnoses

OBJECTIVE

Mucinous ovarian cancer (MOC) is a rare type of epithelial ovarian cancer resistant to standard chemotherapy regimens. We sought to characterize the repertoire of somatic mutations in MOCs and to define the contribution of massively parallel sequencing to the classification of tumors diagnosed as primary MOCs.

METHODS

Following gynecologic pathology and chart review, DNA samples obtained from primary MOCs and matched normal tissues/blood were subjected to whole-exome (n = 9) or massively parallel sequencing targeting 341 cancer genes (n = 15). Immunohistochemical analysis of estrogen receptor, progesterone receptor, PTEN, ARID1A/BAF250a, and the DNA mismatch (MMR) proteins MSH6 and PMS2 was performed for all cases. Mutational frequencies of MOCs were compared to those of high-grade serous ovarian cancers (HGSOCs) and mucinous tumors from other sites.

RESULTS

MOCs were heterogeneous at the genetic level, frequently harboring TP53 (75%) mutations, KRAS (71%) mutations and/or CDKN2A/B homozygous deletions/mutations (33%). Although established criteria for diagnosis were employed, four cases harbored mutational and immunohistochemical profiles similar to those of endometrioid carcinomas, and one case for colorectal or endometrioid carcinoma. Significant differences in the frequencies of KRAS, TP53, CDKN2A, FBXW7, PIK3CA and/or APC mutations between the confirmed primary MOCs (n = 19) and HGSOCs, mucinous gastric and/or mucinous colorectal carcinomas were found, whereas no differences in the 341 genes studied between MOCs and mucinous pancreatic carcinomas were identified.

CONCLUSIONS

Our findings suggest that the assessment of mutations affecting TP53, KRAS, PIK3CA, ARID1A and POLE, and DNA MMR protein expression may be used to further aid the diagnosis and treatment decision-making of primary MOC.

Observations on the origin of ovarian cortical inclusion cysts in women undergoing risk-reducing salpingo-oophorectomy

AIMS

Evidence suggests that up to 70% of high-grade serous ovarian carcinomas (HGSCs) arise potentially from fallopian tube fimbriae, and that many of the remaining cases arise from within the ovary in cortical inclusion cysts (CICs) with a Müllerian phenotype (Müllerian-CICs). It has been proposed that Müllerian-CICs arise either from metaplasia of mesothelial ovarian surface epithelium (OSE) entrapped within the ovary after ovulation or from normal tubal cells entrapped postovulation. However, this proposal is controversial. We therefore conducted a study of CICs in women, most of them BRCA1/2 mutation carriers, undergoing risk-reducing salpingo-oophorectomy at our institution from 2000 to 2014.

METHODS AND RESULTS

We used immunohistochemistry for PAX8, a Müllerian marker, and calretinin, a mesothelial marker to classify CIC cells. In 499 CICs from 59 women, 72.3% were positive for PAX8 (PAX8⁺ ): ≥10% of CIC cells positive; 43.5% positive for calretinin (calretinin⁺ ). The proportion of PAX8⁺ CICs increased from 62.9% in premenopausal to 80.5% in postmenopausal patients. The proportion of calretinin⁺ CICs decreased from 52.6% to 35.6%, respectively. There was significant overlap of PAX8 and calretinin positivity: 82 (16.4%) CICs were PAX8⁺ /calretinin⁺ ; 43 (40.2%) of these 82 demonstrated PAX8⁺ /calretinin⁺ in the same cells.

CONCLUSIONS

These results, and the increased ratio of PAX8⁺ to calretinin⁺ CICs from premenopausal to postmenopausal, show that many PAX8⁺ CICs probably arise from metaplasia of OSE-derived CICs. The proportion of PAX⁺ /calretinin^- CICs arising from OSE-derived CICs is unclear, but our results strongly support the proposal that many Müllerian-CICs arise from OSE via metaplasia.

Cervical Adenocarcinoma: Diagnosis of Human Papillomavirus-Positive and Human Papillomavirus-Negative Tumors

CONTEXT

- Cervical adenocarcinomas span a diverse group of tumors with several distinct histologic tumor types, which include endocervical, endometrioid, intestinal, villoglandular, gastric, signet ring, serous, clear cell, and mesonephric. Diagnosis of cervical adenocarcinoma, especially early diagnosis, poses a significant challenge.

OBJECTIVE

- To review the pathogenesis, diagnostic criteria, immunohistochemical markers, and differential diagnosis of various subtypes of human papillomavirus (HPV)-positive and HPV-negative cervical adenocarcinomas. The paper presents a concise summary of the issues that may be particularly difficult in histopathologic diagnosis, such as differentiating neoplastic lesions from benign mimics, determining the tumor type, differentiating early invasive lesions from adenocarcinoma in situ, measuring the depth of invasion, and, finally, differentiating primary cervical adenocarcinoma from uterine endometrioid adenocarcinoma and tumors metastatic from other primary sites.

DATA SOURCES

- The study employed a PubMed search of recently published reports.

CONCLUSIONS

- Early detection of HPV-positive tumor types may be aided with the expansion of HPV testing; however, early diagnosis of HPV-negative cervical adenocarcinomas will continue to pose a challenge and may require the development of additional molecular testing techniques.

Intestinal differentiated mucinous adenocarcinoma of the endometrium with sporadic MSI high status: a case report

Background

Intestinal differentiation of primary mucinous adenocarcinoma of the uterine corpus is exceedingly rare in comparison to the approximately 25% rate in endocervical and ovarian mucinous carcinoma. Additionally, little is known about the related genetic and epigenetic alterations, even though large-scale molecular characterisation of the different types of endometrial cancer took place in the TCGA project along the entities defined by the recent WHO classification.

Case presentation

We present a 62-year-old patient harbouring a primary mucinous carcinoma of the uterine corpus with a morphological resemblance to mucinous colorectal adenocarcinoma. The intestinal differentiation was substantiated by CDX2 and CK20 positivity in the absence of PAX8, p16, WT1, p53, ER, PgR, AFP, SALL4 and Glypican3. A high MSI status with MLH1 hypermethylation was revealed by molecular testing.

Conclusion

Intestinal differentiation of mucinous adenocarcinoma of the endometrium is a unique observation. Besides morphology, it obviously can share molecular features of sporadic MSI colorectal cancers. It can be speculated that either CDX2 positive morula formation or intestinal metaplasia of the endometrium as rare conditions might be the origin of carcinogenesis for this type II endometrial cancer. Both conditions were not detectable in this case. Of note, categorising endometrial cancers in genetic subgroups like MSI high cancers alone might lead to the integration of likewise morphologically different tumours like the case presented here with intestinal differentiation. Hence, careful genotype-phenotype correlations are warranted for studies of mucinous adenocarcinoma of the endometrium.

Electronic supplementary material

The online version of this article (doi:10.1186/s13000-017-0629-0) contains supplementary material, which is available to authorized users.

Practical Applications in Immunohistochemistry: Carcinomas of Unknown Primary Site

CONTEXT

-Identification of the site of origin of carcinoma of unknown primary using immunohistochemistry is a frequent requirement of anatomic pathologists. Diagnostic accuracy is crucial, particularly in the current era of targeted therapies and smaller sample sizes.

OBJECTIVES

-To provide practical guidance and suggestions for classifying carcinoma of unknown primary using both proven and new antibodies, as well as targeting panels based on integration of morphologic and clinical features.

DATA SOURCES

-Literature review, the authors' practice experience, and authors' research.

CONCLUSIONS

-With well-performed and interpreted immunohistochemistry panels, anatomic pathologists can successfully identify the site of origin of carcinoma of unknown primary. It is crucial to understand not only the diagnostic uses of the many available antibodies but also the potential limits and pitfalls.

Adenocarcinoma of the thymus, enteric type: report of 2 cases, and proposal for a novel subtype of thymic carcinoma

We report 2 cases of primary thymic adenocarcinoma with enteric differentiation. One carcinoma occurred in a 41-year-old man as a 7-cm-diameter cystic tumor and the other one in a 39-year-old woman as a 6-cm-diameter solid mass. Both tumors were located in the anterior mediastinum. Clinical staging did not reveal any extrathymic tumor. Histologically, the tumors were classified as adenocarcinoma, not otherwise specified, and a mucinous (colloid) carcinoma, respectively. Immunohistochemically, both tumors were positive for cytokeratin 20 (CK20), CDX2, and carcinoembryonic antigen, reflecting enteric differentiation. A review of the literature on 43 other cases of primary thymic adenocarcinomas suggested 11 further cases with enteric differentiation, as assessed by CK20 and/or CDX2 expression. We propose that thymic adenocarcinoma with enteric differentiation represents a novel subtype of thymic carcinoma. It is mostly of mucinous morphology and frequently associated with thymic cysts. The clinical outcome is variable. Recognition of primary thymic adenocarcinoma with enteric differentiation is helpful for the differentiation from metastatic disease, mainly from the gastrointestinal tract.

Endometrioid adenocarcinoma with simultaneous endocervical and intestinal-type mucinous differentiation: report of a rare phenomenon and the immunohistochemical profile

Abstract

Intestinal differentiation in the endometrium is rare with only case reports in the international literature. We describe a case of simultaneous endocervical and intestinal-type mucinous differentiation with goblet cells arising in a FIGO grade 1 endometrioid adenocarcinoma. The patient had no involvement of the myometrium, cervix, or extra-uterine sites. There were no intestinal metaplastic changes of the endocervical canal. The etiology of this change is unknown, although recent reports suggest an association with hyperestrogenism.

Virtual slides

The virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1209512176931698

Immunohistochemistry of colorectal carcinoma: current practice and evolving applications

The relatively high incidence of adenocarcinoma of the colon and rectum (colorectal carcinoma) in the general population makes its pathologic diagnosis one of the more frequent exercises in anatomical pathology. Although typically mundane in the primary setting, the correct identification of metastatic colorectal carcinoma or exclusion of metastatic disease from carcinoma arising in other anatomical foci can be problematic. The advent of targeted therapies and refinement of more traditional cytotoxic chemotherapeutic regimens mandates not only a more confident appraisal of site of origin but also assessment of those tumor-specific features that may alter therapeutic decisions. Despite the exponential increase in our understanding of the molecular pathogenesis of colorectal carcinoma, immunohistochemistry remains the foundation for resolution of these problematic cases and the number of antibodies available to the practicing pathologist continues to expand at a steady rate. In some cases, immunohistochemistry may also provide valuable prognostic information, either independently or as a surrogate marker for a specific route of carcinogenesis such as microsatellite instability. This review will focus on the use of new and more established immunohistochemistry markers in the diagnosis of colorectal carcinoma, with an emphasis on aberrant staining patterns of the various colorectal carcinoma subtypes as well as the utility of these markers in specific differential diagnostic settings.

Endometrial carcinomas: a review emphasizing overlapping and distinctive morphological and immunohistochemical features

This review focuses on the most common diagnostic pitfalls and helpful morphologic and immunohistochemical markers in the differential diagnosis between the different subtypes of endometrial carcinomas, including: (1) endometrioid versus serous glandular carcinoma, (2) papillary endometrioid (not otherwise specified, villoglandular and nonvillous variants) versus serous carcinoma, (3) endometrioid carcinoma with spindle cells, hyalinization, and heterologous components versus malignant mixed müllerian tumor, (4) high-grade endometrioid versus serous carcinoma, (5) high-grade endometrioid carcinoma versus dedifferentiated or undifferentiated carcinoma, (6) endometrioid carcinoma with clear cells versus clear cell carcinoma, (7) clear cell versus serous carcinoma, (8) undifferentiated versus neuroendocrine carcinoma, (9) carcinoma of mixed cell types versus carcinoma with ambiguous features or variant morphology, (10) Lynch syndrome-related endometrial carcinomas, (11) high-grade or undifferentiated carcinoma versus nonepithelial uterine tumors. As carcinomas in the endometrium are not always primary, this review also discusses the differential diagnosis between endometrial carcinomas and other gynecological malignancies such as endocervical (glandular) and ovarian/peritoneal serous carcinoma, as well as with extra-gynecologic metastases (mainly breast and colon).

Atypical polypoid adenomyoma of the uterus: an immunohistochemical study on 5 cases

Immunohistochemical studies of atypical polypoid adenomyoma (APA) of the uterus are very rare. Five cases of APA were retrieved from the surgical cases of our laboratory. The ages were 38, 41, 54, 65, and 77 years (mean ± SD, 55 ± 14.6 years). The diameters of APA were 1.2, 1.9, 2.3, 3.2, and 7.0 cm (mean ± SD, 3.12 ± 2.00 cm). Histologically, APA consisted of complex glandular element and mesenchymal fibromuscular element. No endometrial stroma was present. Mucins were found in the glands but not in the mesenchyma. The glands were consistently positive for pancytokeratin (AE1/3, CAM5.2), cytokeratin (CK) 7, CK8, CK18, CK19, vimentin, CA125, estrogen receptor, progesterone receptor, MUC1, and MUC6. The glands were consistently negative for CK14, CK20, CEA, epithelial membrane antigen, S100 protein, p53, CD10, MUC2, and MUC5AC. Some cases were positive for CK34βE12 (4/5), CK5/6 (4/5), and CA19-9 (4/5). The Ki-67 labeling ranged from 3% to 10%. The mesenchymal element was consistently positive for vimentin, α-smooth muscle actin, estrogen receptor, progesterone receptor, and CD10, while consistently negative for pancytokeratin (AE1/3, CAM5.2), CK34βE12, CK5/6, CK7, CK8, CK14, CK18, CK19, CK20, CEA, epithelial membrane antigen, S100 protein, CA125, CA19-9, p53, MUC1, MUC2, MUC5AC, and MUC6. Some cases were positive for desmin (2/5). Ki-67 labeling ranged from 1% to 8%. In conclusion, the immunoprofile of APA was reported. The findings provide basic knowledge of APA of the uterus.

High-Grade Endometrial Carcinomas

High-grade endometrial carcinomas are a heterogeneous group of clinically aggressive tumors. They include FIGO grade 3 endometrioid carcinoma, serous carcinoma, clear cell carcinoma, undifferentiated carcinoma, and malignant mixed Müllerian tumor (MMMT). Epidemiologic, genetic, biologic prognostic and morphologic differences between these entities are striking in prototypic cases, yet substantial overlap exists and diagnostic criteria and therapeutic approaches that account for the group's diversity are currently insufficient. FIGO grade 3 endometrioid carcinoma demonstrates solid, trabecular or nested growth and may resemble poorly differentiated squamous cell carcinoma. Endometrioid glandular differentiation is usually focally present. Serous carcinoma usually displays papillary architecture but glandular and solid patterns may predominate. Tumor cells typically display diffuse and severe atypia. Clear cell carcinoma should be diagnosed by recognizing characteristic papillary or tubulocystic architecture with cuboidal tumor cells showing atypical but uniform nuclei. Cells with clear cytoplasm are frequently but not always present. On the other hand, clear cells may be encountered in endometrioid and serous carcinomas. Immunohistochemical stains for p53, p16, ER, PR, mib-1, hepatocyte nuclear factor 1β and pan-cytokeratin can be helpful in classifying these high-grade carcinomas. They should be used in concert with thorough morphologic examination, as part of a rational panel of markers and only in specific circumstances. Although these tumors may appear clinically and even morphologically similar, demographic and epidemiologic features as well as patterns of spread and treatment modalities differ.

Neoplastic Lesions of the Cervix

This review presents a discussion of the gross and microscopic features, diagnosis, differential diagnosis, and prognosis of neoplastic lesions of the cervix. Biomarkers are discussed for each entity presented - cervical intraepithelial neoplasia, squamous carcinoma, glandular neoplasms, adenocarcinoma in situ, adenosquamous carcinoma, and others.